Fellaini was injured in a wild 4-3 win over Bosnia-Herzegovina in World Cup qualifying.
Belgium manager Roberto Martinez has confirmed that Marouane Fellaini suffered knee ligament damage in the Red Devils' match against Bosnia-Herzegovina on Saturday, per Sky Sports.
The Belgian Football Association reported that the Manchester United midfielder would only miss a "couple of weeks" after leaving the field in pain, but the latest news coming from the camp points to a potentially longer hiatus for the former Everton man.
"We are all worried about Fellaini. We fear that there's ligament damage," Martinez had said after the game. And according to Sky, the manager's fears have been confirmed.
Fellaini is set to miss Belgium's qualifier against Cyprus on Tuesday, and will miss United's match against Liverpool on Saturday. United also have crucial games against Benfica, Spurs and Chelsea marked down, and it's now likely that Fellaini will be ruled out for all of them.
The Belgian's United teammate Juan Mata has sent him a message, sympathizing over the injury and wishing him a speedy recovery.
"We will try to extend our good run of results since the season started," the Spaniard said. "I also hope that none of my team-mates has physical problems in the second game with the national teams as it was the case with Fellaini, to whom I wish a speedy recovery."